1. Field of the Invention
The present invention relates to a radiotherapy system, and more particularly relates to a radiotherapy system for performing radiotherapy with precise irradiation.
2. Description of Related Art
A radiotherapy is known which a patient is treated by radiating a therapeutic radiation to an affected area (tumor). As the therapeutic radiation, a radiation generated by the bremsstrahlung is shown as an example. The radiotherapy is desired to more precisely irradiate the affected area with a predetermined dose of the therapeutic radiation, and change of energy (energy distribution) and intensity of the therapeutic radiation is desired to be smaller.
Japanese Laid-Open Patent Application JP-P2005-033463A discloses a waveguide rotary joint which needs no chalk construction requiring mechanical accuracy, and can thereby suppress attenuation of electromagnetic wave in a circular waveguide and reduce possibility of discharging from the circular waveguide. In the waveguide rotary joint to which a square waveguide is connected at respective end parts of the circular waveguide having a rotary coupling part whose both end parts can rotate relatively around a center line of axis, the waveguide rotary joint is characterized by converting an electromagnetic wave transmitted in TE10 mode inside an input side square waveguide into that in TE01 mode in a connection part with the above mentioned input side square waveguide and the above mentioned circular waveguide and transmitting it inside the circular waveguide, and converting the above mentioned electromagnetic wave from the TE01 mode into the TE10 mode again in a connection part with the above mentioned circular waveguide and an output side square waveguide and outputting it to the above mentioned output side square waveguide.
Japanese Patent JP 3746744B discloses a radiotherapy apparatus with superior treatment performance. The radiotherapy apparatus is characterized by including: a radiation head, a supporting and moving mechanism, a microwave generator, and a waveguide part. The radiation head has a therapeutic radiation generation part composed of an electron gun, a linear accelerator, and a target and a gimbal mechanism for oscillating the therapeutic radiation generation part. The supporting and moving mechanism is for supporting and moving this radiation head on a predetermined spherical coordinates. The microwave generator is for generating microwave to be supplied for this head, which is arranged on a static position. In the waveguide part, one end part is electromagnetically connected to the microwave generator and another end part is electromagnetically connected to the linear accelerator. A waveguide of said waveguide part mounted on said gimbal mechanism and a waveguide of said waveguide part from said microwave generator are connected by a flexible waveguide.
Japanese Laid-Open Patent Application JP-A-Showa, 62-206798 discloses a linear accelerator which is small sized, inexpensive, and high-precision, realized by mounting an extremely small sized and light-weighted acceleration tube on the acceleration body and by connecting the acceleration tube to a microwave source with a flexible waveguide. The linear accelerator is characterized in that the linear accelerator body is connected to the microwave source with the stretchable and flexible waveguide so as to rotate and move in upward and downward direction.
Japanese laid-Open patent Application JP-P2001-009050A discloses a radiotherapy device. In the radiotherapy device, the electron beams which are made incident to the magnetic field range of the second main electromagnet is deflected by 180 deg., and draws a second circular arcuate orbit. The electron beams along the second orbit is deflected by 180 deg. by the first main electromagnet and passes through a circular arcuate orbit to be emitted to a linear accelerator and is accelerated by the linear accelerator again. Mass is increased in the electron beams in this case so that the third orbit being the larger circular arcuate one is drawn when 180 deg. deflection is obtained by the second main electromagnet 107. The electron beams are deflected by a deflection magnet, a target is irradiated with them, X-rays are generated, a visual field range is restricted by a collimator and a testee body set on a diagnosing device is irradiated with the electron beams.
Japanese Laid-Open Patent Application JP-A-Showa, 50-105048 discloses a high frequency coupler. The high frequency coupler includes a first waveguide part, a co-axial waveguide, and a second waveguide part. The first waveguide part has at least one high frequency coupling window with a slit shape opened on a tube wall of the waveguide in a direction parallel to a tube axis direction of the waveguide. The co-axial waveguide is coupled with a window formed in a short-circuit board at an end of the first waveguide part along an extension of the tube axis direction, and a part of a central conductor thereof is inserted into the first waveguide part through the window. The second waveguide part has a tube axis direction approximately perpendicular to that of the first waveguide part and is provided opposite the first waveguide behind the co-axial waveguide.
Japanese laid-Open patent Application JP-P2002-253687A discloses a radiotherapeutic apparatus. In the radiotherapeutic apparatus, the head part which is positioned with a manipulator and irradiates a site to be treated of a patient with X rays is provided with an X-ray generator which accelerates electrons from an electron gun by microwaves and hits a target to generate the X rays. A microwave source for supplying the microwaves used for the acceleration of the electrons is provided on the side of the base part of the manipulator. The head part and the microwave source are connected with a waveguide.